Ski binding



am 1969 B. E. BERLENBACH SKI BINDING Filed Jan. 10, 1967 United States Patent 3,430,971 SKI BINDING Bernard E. Berlenbach, 220 Shoreline Highway, Mill Valley, Calif. 94941 Filed Jan. 10, 1967, Ser. No. 608,315 US. Cl. 28011.35 12 Claims Int. Cl. A63c 9/ 081 ABSTRACT OF THE DISCLOSURE A ski binding comprising a support base adapted to be mounted on a ski runner and a body member including a boot-holding means for releasably connecting a ski boot to the runner, the body member being provided with a vertical bore fitted with a pivot pin for mounting it relative to the runner, a central cavity housing a cam member and including means for sealing the cavity from dirt, grime, etc. exterior of the body member, and a horizontal bore intersecting the vertical bore and pivot pin fitted with a cam piston slotted to engage the pivot pin and having a head fitted with a roller adapted to engage the face of the cam member with minimum friction.

Background of the invention This invention relates to ski bindings and more particularly to bindings which operate to release a ski boot from a ski runner when a reaction force acts on the binding having an amplitude beyond a preselected threshold level.

It is an object of the present invention to provide a compact ski binding adapted to release a skiers boot when either fast action reactive forces act on the boot above the threshold level of the binding as well as a binding that responds to more slowly acting forces which may only slightly exceed the threshold level of the binding but which act on the skiers boo-t for a relatively long period of time.

Ski bindings are designed to release when a preselected threshold level is exceeded by external forces acting on the binding. To allow for release, each binding may include a boot-holder means yieldably attached to a ski runner on a pivot and held against rotation by selectively yieldable means such as a movable piston sliding in a bore formed in a body member and responsive to the action of a relatively strong compression spring urging the piston against a conforming camming surface solid to the ski runner. The threshold level of each binding is adjustable say, for example, by changing the compression of the spring. In operation, as the skier falls from an erect position, external forces are created which act through the skiers boots on his bindings. If such forces are far above threshold, the operation of the bindings is usually swift, precise and reliable. The piston head rapidly travels along the adjacently provided camming surface in response to the external forces. When the binding reaches a release position angularly measurable from the nadir position of the piston, the skiers boot is released from the ski runner.

It has been found that serious injuries often occur as a skier tumbles even though the skier uses a releasable type of binding. It is believed a contributing factor in many of such accidents is a skiers natural tendency to try to regain his balance after initially losing his stability. As he starts to fall, his natural tendency is to fight to regain his balance. During this period (which can last several seconds) the reaction forces may only slightly exceed the threshold level of his binding but endure for a relatively long time period. Such forces are extremely dangerous even though they only all) 3,430,971 Patented Mar. 4, 1969 slightly exceed the threshold level because the bindings do not release as they should due to imprecision in their manufacture and operation. Accordingly, the reactive forces may endure a sufficient length of time to cause serious injury to the skier. It is believed that this type of injury results from fatigue to the skiers associated bone and support anatomy as the reactive force is continued over a relatively long time period. Since inexperienced skiers more often lose their balance, such injuries are more common to them. Accordingly, the skier is compelled to adjust the threshold level of his bindings to a minimum level to be sure of their proper operation under all conditions. Such conservatism compensates for his inability to rely on his binding to accurately and precisely release his boot at a preselected threshold level.

Summary of the invention Briefly, the present invention provides a precision ski binding which includes a support base adapted to be mounted on a ski runner and a body member including boot holding means for releasably connecting a ski boot to the runner. The body member is provided with a vertical bore fitted with a pivot pin for mounting it relative to the support base, a central cavity housing a cam member and inclosing means for sealing the cavity from dirt, grime and other foreign objects exterior of the body member, and a second horizontal bore intersecting the vertical bore and fitted with a cam piston slotted to engage the pivot pin over a central region and having a head provided with a roller in engagement with the face of the cam member. The cam roller is also pivotally mounted by a shaft forming a pivot axis to said piston.

When external forces act on the skiers boot above the threshold level of the binding (determined by spring means supported on the body member at one end of the cam piston), rotation of the body member and cam roller-piston occurs. The cam roller is adapted to roll, with minimum resistance, on the surface of the cam face as the cam piston pivots relative to the cam memher.

The cam face is adapted to be concave with respect to the axis of the cam piston and has a contour varying with distance along a path traversed by the cam roller so as to compensate for relative changes in condition of the spring means as the binding releases the ski boot from the ski runner. Accordingly, as the cam roller pivotally traverses the cam face to release the skiers boot from the binding and runner, resistive forces opposing the external forces remain substantial- 1y constant until release irrespective of any increases in the net compressive strength of the spring means.

The cam face is provided with a planar base means attached to the cam face and disconnectably connectable to the support base so as to be solidly fixed thereto during release of the binding but to be easily removable therefrom when replacement is desired.

Description of drawings To afford a clearer understanding of this invention, and the manner in which it may be carried out in practice, reference is now made to the accompanying drawings in which:

FIGURE 1 is an elevational viewpartially cut away-illustrating a ski binding of the present invention positioned on a ski runner for cooperative release of a ski boot from the runner;

FIGURE 2 is a sectional view taken along line 22 of FIGURE 1 in which a pivotal cam roller-piston is shown in contact with the dwell section (nadir) of the cam member of the binding;

FIGURE 3 is another section view taken along a line parallel with line 2--2 of FIGURE 1 in which the pivotal cam roller-piston is shown in contact with the lift section of the cam member to illustrate the binding in its release condition;

FIGURE 4 is a detail-in perspectiveof the cam roller-piston of FIGURES 1-3; and

FIGURES 5 and 6 are details-in section-of two embodiments of the cam roller-piston of the binding of the present invention illustrating separate bearing means for the cam roller.

Description of preferred embodiments Reference is now made to the drawings. FIGURE 1 illustrates a preferred embodiment of the invention depicting ski binding 10 adapted for disconnectably connecting ski boot 11 relative to ski runner 12. The sole of the boot 11 is shown engaged with a toe hold 19 with freedom of turning movement about pivot pin 20. The boot is urged into contact with toe hold 19 by suitable forcing means located at the heel portion of the boot such as a thong and heel spring (not shown). A springloaded detent 22 holds toe hold 19 relative to the forward portion of the binding to permit the toe hold to swivel with the binding and not wedge the boot between the binding and the rearward forcing means at the heel portion of the boot. When the skier begins to lose his upright stability and fall, external forces act through his boot upon the binding. As the skier fights to regain his balance and upright stability, however, the external forces may be slow acting. If they are also of low amplitude, say just above the threshold of the binding, the binding may not release due to the imprecision in forming the relatively releasing sections of the binding. Obviously if the binding does not release, the skier may be severely injured.

To release a ski boot from a ski runner in response to both fast acting forces and slow acting forces irrespective of their magnitude above threshold, binding 10 in accordance with the present invention includes a base support 25 fixedly attached to the runner 12 by screws 27 and a central body member 26 pivotally attached to base support 25 through pivot pin 21.

Central body member 26 is attached to the toe hold 19 by fastening pivot pin 20 between a pair of longitudinally extending bosses 28. Over its central region is provided a vertical bore 29 fitted With the pivot pin 21. As indicated in FIGURE 1, the lower end of pin 21 is suitably secured in the base support 25 to allow pivoting of the releasing element of member 26 normal to the ski runner.

Intersecting vertical bore 29 at pin 21 is horizontal bore 30. It communicates cup-shaped cavity 31 at the interior of member 26 with the forward exterior thereof. Cavity 31 is fitted with cam member 32 in alignment with the axis A of the horizontal bore 30. A vertically extending cam face 33 of the cam member 32 is seen to extend over nearly the full height of the cavity 31; a planar base 34 normal to cam face 33 is unitarily formed at the lower edge of the face and is solidily attached to the support base 25 by detents 35 seatable with openings 36 in support base 25. Although cam member 32 is solidly fixed relative to support base 25 and ski runner 12, it is capable of easy renewal should dirt, grime, etc., render it unserviceable, by releasing pin 21 from contact with support base 25 and swinging the member 26 from contact with the support base 25.

During normal operation of the binding, cavity 31 is not open to easy intrusion by dirt, snow, grime, etc., but is sealed along its lower edge by sealing disk 37. The disk 37 includes a planar end section in contact with a conforming surface of the cavity 31, say a groove, and a central bore through which extends boss 38 of the base member 25. It may also be attached by other types of fasteners, such as screws, if a more positive form of attachment is desired.

Cam roller-piston 40 is slidably mounted within horizontal bore 30 and has a cam roller 41 in urging contact with cam member 32. In addition to cam roller 41, it also includes a cam piston 42 to which the cam roller 41 is pivotally mounted by shaft 43 normal to the ski runner. Shaft 43 is aligned parallel to pivot pin 21 so that as body member 26 is pivoted about the pin 21 the cam roller 41 rolls over cam face 33 with minimum resistance.

Coil 44 is operatively contacted at the rear end of cam piston 42 opposite to cam roller 41. When compressed within the bore 30, it urges the cam roller 41 into contact with cam face 33. Plug 45 is threaded within bore 30 into operative contact with the rear end of the coil and is capable of varying the extent of its urging force-and hence threshold level of the binding-by varying the position of the plug 45 relative to pin 21. The magnitude of the urging force of coil 44 establishes a resistive force between the cam face 33 and cam roller 41 which resists the action of the external forces (torsional) acting through the skiers boot upon his bindings.

Cam piston 42 is adapted to slide in horizontal bore 30 simultaneously with its azimuthal rotation relative to pin 21 as the body member rotates. It is, however, prevented from rotating about its axis of symmetry. As indicated in FIGS. 2 and 3, a slot 48 is provided over its central region through which pin 21 passes. The length of the slot 48 should be at least long enough to allow full' longitudinal movement of the cam roller-piston 40 during operation of the binding. The width of the slot, however, should conform to the diameter of pin 21 to form a sliding fit therewith. The axial stacking of the horizontal and vertical bores and pinning of the cam rollerpiston 40 by pin 21 not only reduces the total length of the binding-thereby forming a more compact design-- but also allows the shaft 43 at the forward end of the cam piston 42 to remain in parallel alignment with pin 21 during longitudinal travel of the piston. Accordingly, cam roller 41 slides relative to cam face 33 with minimum friction irrespective of the direction of the external forces acting on the cam roller-piston.

FIGURE 4 illustrates the cam piston 42. As indicated, it is provided with elongated bosses 49 at its rearward end. They form a recess 50 into which the cam roller 41 is seated. The shaft 43 rotatably secures the cam roller 41 in the recess between the bosses 49 with its axis of rotation parallel to that of the cam piston 42 as previously mentioned.

FIGURE 2 illustrates the operation of the binding Where the incident external forces are below the threshold level of the binding. The cam roller-piston 40 is positioned at the nadir of curvature 56 of the cam face 33, i.e., where the coil 44 is at its minimum energy level relative to cam member 32. The curvature of cam face 33 is seen to be concave relative to the cam roller-piston 40 and preferably is symmetrical to a horizontal axis coincident with axis A of bore 30. Each section of cam face below or above its axis of symmetry is seen to begin at the nadir curvature 56 and terminate at edges 57 of the cam face. In the plane of the cam roller-piston 40, the nadir 56 and edges 57 define a path traversable by the cam roller 41 during operation of the binding. The binding releases the booth before the cam roller 41 reaches either edge 57 however, say when the cam roller-piston 40 has rotated through an angle of 30 relative to the nadir section '56.

As indicated in FIGURE 2, the line of action of coil 44when the cam roller 41 is positioned at the nadir of curvature 56-is coincident with both the axis A of bore 30 and the axis of symmetry of the cam member 32. It also passes through pivot pin 21, shaft 43 and the contact line between the cam roller 41 and the cam face 33. It may also pass through spring-loaded detent 22 securing toe hold 19 relative to the body member 26.

Adjustment in the active length of the coil 44and hence the magnitude of the threshold level of the binding--is through rotation of plug 45 for axial movement relative to pivot pin 21. Plug 45 also has a longitudinal axis coincident with the line of action of the coil 44.

FIGURE 3 illustrates the binding of the present invention in its release condition. External forcesabove threshold-have acted on the binding through the skiers boot. Cam roller-piston 40 has undergone rotation about solidly fixed pivot pin 21 relative to the cam member 32 along a path defined by nadir section 56 and edges 57 to the release position shown. At the indicated release position, the cam roller-piston 40 is seen to form an angle a with the axis of symmetry of the cam member 32. The angle or is the azimuthal angle of rotation formed between axis A of the horizontal bore 30 and the axis of symmetry of the cam member 32. When the angle a is equal to a predetermined value, say 30, the skiers boot is released from the binding. The line of action of the coil 44 is coincident with the axis A of the bore 30 and still passes through pivot pin 21 and the spring-loaded detent 22 holding toe hold 19 relative to the body member 26. As indicated, the toe hold 19 has also been pivoted about its pivot pin 20 to compensate for the relative change in the axial location of the boot and binding to prevent the boot from wedging during rotation of body member 26.

Between nadir section 56 and the release position of the binding, the radial distance from the pivot pin 21 to the contact line 55 of the cam roller 41 and earn face 33 progressively decreases as the cam roller 41 travels along the cam face 33. The distance is maximum when the cam rollerap-iston 40 is at the nadir section 56 and is of minimum value at the release position of the binding. The change in curvature of the cam face causes the cam roller-piston 40 to undergo axial movement relative to the bore 30 simultaneous with its rotation about the fixed pivot pin 21. Accordingly, the active length of the coil 44 is shortened increasing the urging force of the binding. But in accordance with the present invention, the reactive forces of the binding which resist the external forces causing rotation of the body member 26 do not increase with the rotation of the cam roller along the cam face 33. Rather, they remain substantially constant until the azimuthal angle for release of the binding is attained.

As indicated in FIGURE 3 at the release position of the binding the line of action of coil 44 is no longer aligned with the contact line 55 of the cam roller 41 in the cam face 33. Instead, it forms an angle 5 with an axis normal to the cam face and intersecting the contact line 55 and the shaft 43 about which the cam roller 41 rotates. Accordingly, as the cam roller 41 travels along the cam face, the urging force of the coil 44 is resolved into two components-one normal and one parallel to the cam face 33. The component normal to the cam face proportional to the resistive forces of the binding can thus be equalized along the path of travel of the cam roller so that the external forces causing rotation of the binding are resisted by forces which remain constant over the path of travel of the cam roller 41 irrespective of the fact that the total urging force of coil 44 is progressively increasing with angular movement of the cam rller-piston 40. Between the nadir section 56 and the release section of the binding, the magnitude of the angle ,8 is progressively changed as a function of the magnitude of the angle of rotation of the cam roller-piston 40, i.e., angle a, to maintain the above relationship. In this regard, several factors are relevant in maintaining a correct magnitude for angle as a function of angle or, among which are. the contour of the cam face 33 relative to its axis of symmetry; the size of the cam roller '41, and the distance between pivot pin 21 and the cam face 33 at the nadir section of the cam member.

After the ski boot is released from the binding, both angular and axial movement of the cam roller-piston 40 ceases. The coil 44 remains in a compressed condition even though the external forces acting on the binding are now zero. Thus a component of the urging force exists to cause reverse movement of the cam roller-piston 40 along the cam face to return the roller to the nadir section 56 of the cam member 32.

FIGURES 5 and 6 illustrate cam roller 41' attached to the cam piston 42' through a bearing 60. The purpose of bearing 60 is to enhance the reaction capability of the binding to external forces above the threshold level of the binding. Bearing 60 may be formed of any material compatible with the environmental conditions in which the binding is used. A preferred material is Teflon. In FIGURE 5, the bearing 60 is positioned between a central bore of the cam roller 41' (which may be a sphere) and its fixed shaft 43'. Shaft 43' extends between longitudinally extending bosses 49' which form a recess 50' for receiving a portion of cam roller 41. In FIGURE 6, bearing is solidly fixed to the bosses 49' within openings 63. The bearings rotatively receive shaft spokes 64 permanently aflixed to the cam roller 41' to allow easy rotation of the cam roller 41' relative to the cam piston 42.

While several embodiments of the invention have been illustrated and described in detail, it is to be expressly understood that various changes may also be made in the design and arrangement thereof without departing from the spirit and scope of the invention. For example, instead of the cam member 32 being solidly fixed relative to the support base 25, and the .cam roller-piston 40 pivotally mounted relative thereto, the function of these parts may be reversed without departing from the intended scope of the invention.

I claim:

1. A ski binding for yieldably and pivotally mounting a ski boot for a ski runner so as to allow rotational release of said boot from said runner in response to external forces acting on said binding through said boot above a preset threshold level comprising:

(a) a support base adapted to be fixedly mounted to said ski runner;

(b) a body member including boot-holding means for releasably connecting said ski boot to said body member, said body member having a vertical central bore fitted with a pivot pin for pivotally mounting said body member to said support base, and a horizontal bore having an axis of symmetry, said horizontal bore terminating in communication with a cavity formed within said body member, said body member adapted to pivot about said pivot pin in response to said external forces so as to release said ski boot from said boot-holding means at a preselected angle of rotation;

(c) a cam member fixedly mounted to said support base and including a curved cam face positioned within said cavity of said body member adjacent to said horizontal bore;

((1) a camroller-piston having a portion slidably positioned within and supported by said horizontal bore so that said cam roller-piston follows said body member in rotation about said pivot pin in response to said external forces, and a more remote portion positioned within said cavity, said cam roller-piston including a cam roller pivotally mounted to said remote portion in operative contact with said cam face of said cam member, said axis of rotation of said cam roller being substantially parallel to that of said body member, said cam roller piston adapted to remain stationary with respect to said cam base at a nadir section thereof when said external forces are below threshold but adapted, as said cam rollerpiston and said body member rotate about said pivot pin in response to said external forces above threshold, to traverse an arcuate path along said cam face to said preselected angle of rotation for release of said ski boot from said boot-holding means, and simultaneously to undergo axial movement relative to said horizontal bore in response to change in contour of said cam face along said arcuate path of travel, said cam roller being adapted to roll over said cam face so as to reduce frictional forces acting therebetween;

(e) sealing means attached between said body member and said support base so as to seal said cam member and said cam roller-piston from foreign objects external to said body member which inhibit operation of said binding; and

(f) spring means attached between said body member and said cam roller-piston adapted to establish an urging force for urging said cam roller into con tact with said cam member so as to establish a resistive force to rotation of said body member about said pivot pin, said spring means adapted to change operative state in response to said axial movement of said cam roller-piston so as to establish a retrieving force for returning said cam roller-piston to its original location at said nadir section after said external forces above a threshold are terminated.

2. A ski binding in accordance with claim 1 in which said cam member also includes a planar base support integral with said cam face, said planar support including attaching means for disconnectably connecting said cam member to said support base so that said cam member is fixed solidly to said base during operation of said ski binding but is easily removable therefrom when renewal is desired.

3. A ski binding in accordance with claim 1 in which said cam roller-piston is further characterized by hearing means adapted for location between said cam roller and said cam piston.

4. A ski binding in accordance with claim 1 in which said cam roller-piston includes shaft means adapted to pivotally attach said cam roller relative to said cam piston.

5. A ski binding in accordance with claim 4 in which said cam roller-piston is further characterized by provision of a slot over said portion slidably positioned within said horizontal bore for slidably receiving said pivot pin, said slot adapted to prevent rotation of said cam rollerpiston relative to its axis of symmetry but allow said cam roller-piston to move axially along said axis and pivot in an angular direction about said pivot pin in response to said external forces above said threshold level of said binding.

6. A ski binding in accordance with claim 5 further characterized in that said contour of said cam face varies with respect to said pivot pin so as to cause said urging forces provided by said spring means to be resolved into a resistive force acting between said cam roller and said cam face in a direction normal to said cam face and a retrieving force parallel to said cam face for returning said cam roller-piston to its original location at said nadir section of said cam member, said resistive forces being constant along said path of travel of said cam roller and said retrieving force being constantly increasing in proportion with the change in operating state of said spring means.

7. A ski binding in accordance with claim 6 in which said contour of said cam face along said path of travel of said cam roller is defined with respect to said pivot pin by a series of radial distances which vary from a maximum at said nadir section of said cam member to amore reduced value at said preselected angle of rotation where said ski boot is released from said ski binding, each of said radial distances being measured along an axis normal to said cam face and intersecting the contact line between said cam roller and said cam face and said shaft securing said cam roller to said cam piston, one of said axes being coincident with the line of action of said spring means when said external forces are below threshold and said cam roller-piston is positioned at said nadir section of said member, said other of said axes controllably deviating from coincidence with said line of action of said spring means as said cam roller travels said path wherey said resistive force between said cam face and said cam roller remains substantially constant irrespective of the position of said cam roller along said path. 8. In a ski binding of the type having a cam surface means, a roller means, spring means and at least a first member adapted to be fixedly mounted on a ski and a second member rotatable with respect to a pivot pin on said first member, said second member having means for securing a ski boot thereto, the improvement comprising (a) wall means formed in one of said members defining at least first and second intersecting bores,

(b) cam surface means including a grooved cam face extending substantially at right angles to the axis of symmetry of said second of said intersecting bores and attached to the other of said members,

(0) a piston means operatively connected at one end to said spring means,

(d) shaft means for pivotally mounting said roller means to said piston means at an end remote from said spring means so as to define an axis of rotation for said roller means with respect to said piston means substantially parallel to said curved cam face,

(e) said first bore of said wall means supportingly receiving said pivot means for pivotally mounting said second member to said first member, said second bore supportingly receiving said piston means and said spring means to locate said roller means in operative contact with said cam surface means whereby said spring means urges said roller means into contact with said cam means so as to establish a resisting force threshold level for said members, said piston and roller means remaining stationary with respect to said cam surface means at a nadir section thereof when external forces acting on said binding through a ski boot mounted thereto are below thershold but adapted, as said second member rotates with respect to said first member in response to said external forces above said threshold, to (i) relatively angularly rotate with respect to said cam surface means to traverse an arcaute path along said cam face to a preselected angle for release of said ski boot from said boot holding means, and simultaneously (ii) undergo axial movement relative to said second bore to change the operating state of said spring means,

(if) said cam face of said cam surface means varying in contour along said arcuate path traversed by said cam roller means along said cam face so as rotation therebetween occurs, to cause said urging force of said spring means to be resolved into a resistive force acting between said cam roller and said cam face in a direction normal to said cam face and a retrieving force parallel to said cam face for returning said cam roller and piston means to said original location thereof at said nadir section of said cam surface means after said external forces above said threshold are terminated, and

(g) means for releasably attaching said piston means relative to said pivot pin so as to allow relative axial movement therebetween to prevent rotation of said piston means about its own axis of symmetry as said piston and roller means undergo relative angular movement with respect to said cam means whereby said axis of rotation of said roller means remains substantially parallel to said cam face of said cam surface means during rotation of said first member relative to said second member.

9. The improvement of claim 8 in which said lastmentioned means for releasably attaching said piston means to said pivot means is further characterized by wall means through one of said piston means and said pivot pin through which the other of said piston means and piVOt pin slidably extends.

10. The ski binding of claim 8 in which said lastmentioned means includes slot-like wall means extending through said piston means through which said pivot pin slidably fits.

11. The ski binding of claim 10 in which said slot-like Wall means is located between the ends of said piston means so as to position said roller means and said spring means on opposite sides with respect to said pivot pin to thereby form a ski binding of compact construction.

12.. The ski binding of claim 8 in which the contour of said cam face varies with respect to said pivot pin so as to cause said urging forces provided by said spring means to be resolved into a resistive force acting between said cam roller and said cam face in a direction normal to said cam face and a retrieving forces parallel to said References Cited UNITED STATES PATENTS 3,027,173 3/1962 Beyl 280-1135 3,107,102 10/1963 Ramillon 280-11.35 3,199,885 8/1965! Smolka et al. 280-4135 BENJAMIN HERSH,

JOHN A. PEKAR, Assistant Examiner.

Primary Examiner. 

